1. The Audiology Unit continues to acquire normative data for various aspects of auditory and vestibular function. This data serves as reference ranges of normal performance by which test results can be interpreted, and will be used as control data for comparison to data obtained in various patient groups in our collaborative research endeavors. We are also examining the effects of various methodologies, stimulus characteristics, test equipment, test paradigms, and the influence of non-pathologic subject characteristics (e.g. age, gender) on normal function, and evaluating variability of auditory and vestibular measures over time. To date we have focused on the development of normative and comparative data for tests of otolith function and have made 2 presentations at professional society meetings on this topic (Zalewski et al. 2014) and have a manuscript in preparation. 2. In collaboration with Drs. Griffith and Friedman (NIDCD), Dr. Moore (Cincinnati Childrens Hospital), and Dr. Zobay (Institute for Hearing Research, UK), we examined heritability of temporal and spectral auditory processing skills using non-speech tests. These tests were administered to twin pairs in an effort to determine if auditory processing skills are inherited traits. We have previously identified heritability of speech-based auditory processing skills and this current work extends our research to demonstrate heritability for non-speech stimuli. We have a manuscript in submission. 3. In collaboration with the Dr. Griffith (NIDCD), the Audiology Unit performs auditory and vestibular phenotypic assessments of individuals with enlarged vestibular aqueducts as well as their siblings and parents. Over 90 probands and their families have been ascertained. We continue to search for phenotypic features that predict genotype and clinical prognosis. We have published one manuscript on vestibular characteristics (Zalewski et al., 2015) and have another in preparation. 4. In collaboration with Drs. Friedman and Griffith (NIDCD) and Dr. Zein (NEI), the Audiology Unit continues to study auditory and balance function in persons with Usher Syndrome. We are interested in postural balance skills and their relationship to vestibular and visual function, type of Usher syndrome, genotype, and the progression/decline of these skills over time. Over this reporting period we have one publication (Zein et al., 2014) and have one manuscript in preparation. 5. In collaboration with Dr. Drayna (NIDCD), we evaluated auditory function in a large family with AP4E1 mutations and stuttering. This work is included in a submitted manuscript describing the phenotype of these individuals. 6. In collaboration with Dr. Cunningham (NIDCD), we initiated development of a test protocol to document the effectiveness of an otoprotective methodology for patients receiving ototoxic medications. 7. In collaboration with Drs. Heiss and Chittiboina (NINDS), we are investigating hearing, electrophysiologic auditory function, vestibular function, and postural balance in persons with neurofibromatosis type 2 (NF2). We are interested in the relationship of these measures to cochleovestibular schwannoma size, the natural history of disease progression, and sensitivity of these assessments in early detection with the goal of improving clinical management of those with NF2. 8. In collaboration with Dr. Porter (NICHD), we participated in a phase 1 trial of hydroxypropyl beta cyclodextrin (HPBCD) for treatment of Neimann Pick Type C disease. Our roles include monitoring of auditory function and grading of ototoxicity, participation on the safety committee, participation in the NIH/NCATS NPC Ototoxicity Meeting, and in other discussions regarding this treatment. We presented our preliminary research on ototoxicity related to HPBCD at the Association for Research in Otolaryngology meeting in 2015. 9. In collaboration with Dr. Goldbach-Mansky (NIAMS) we continued evaluation of auditory manifestations of neonatal onset multi-system inflammatory disorder (NOMID), familial cold auto-inflammatory syndrome, and Muckle-Wells syndrome and the effectiveness of several drug therapies. We are currently analyzing data and preparing a manuscript examining the course of hearing over a 5-year monitoring period for those who have been treated with anakinra. 10. In collaboration with Dr. Holland, (NIAID) we collected research data and contributed to a manuscript examining the phenotypic effects of GATA3 insufficiency (Lawrence et al., 2015). 11. In collaboration with Dr. Gunay-Aygun (NHGRI) we presented a poster at a professional society meeting that highlighted our research on auditory function, including evoked potentials, in persons with Alstrom syndrome (Lindsey et al., 2015) and are currently developing a manuscript. 12. In collaboration with Dr. Venditti (NHGRI) we evaluated and analyzed the natural history of auditory function in patients with methylmelonic acidemia. This resulted in a poster presentation (Manoli et al., 2015) at a professional society meeting. A manuscript is in preparation. 13. In collaboration with other NIH investigators, we are evaluating hearing, electrophysiologic auditory function, and auditory processing manifestations in persons with oculocutaneous albinism (Adams, NHGRI), neurofibromatosis type 1 (Widemann, NCI), congenital disorders of glycosylation (CDG)(Wolfe & Gahl, NHGRI), Moebius syndrome (Mannoli, NHGRI), and gangliosidosis types 1 and 2 (Tifft, NHGRI). We are interested in the auditory phenotype, including processing of dichotic and other complex sounds, and relationships to other aspects of the disease/disorder and genotype. We contributed to professional society poster on the topic of hearing loss in persons with CDG (Ferreira et al. 2015). 14. We continue to evaluate natural history of auditory function in persons with Fanconi anemia and other inherited bone marrow failure syndromes (IBMFS) (Alter, NCI), McCune-Albright syndrome and polyostotic fibrous dysplasia (M. Collins, NIDCR), von Hippel-Lindau disease (Lonser, NINDS), Smith-Magenis syndrome (Smith, NHGRI), WHIMS (McDermott, NIAID), osteogenesis imperfecta (Marini, NICHD), Y-Chromosome variants (Muenke, NHGRI), xeroderma pigmentosum and trichothiodystrophy (Kraemer & Digiovanna) and the Undiagnosed Diseases Program (Gahl, NHGRI). We are interested in the auditory phenotype, natural history of hearing, and relationships to other aspects of disease/disorder and genotype. 15. In collaboration with investigators from NINDS (Wasserman & LoPresti), we are evaluating hearing and vestibular function in persons with exposure to breacher explosions. We are examining the effects of repeated exposures on the auditory and vestibular systems. 16. In collaboration with other investigators the NIH, we continue to implement and analyze studies of the auditory and/or vestibular system of persons participating in clinical procedures or therapies in which there may be risk of ototoxicity. These include aminoglycosides for mycobacterium infections (Holland, NIAID & Olivier, NHLBI), antineoplastic compounds (Hassan, NCI), radiation therapy for brain tumors (Warren, NCI), and transcranial magnetic stimulation (Hallett & Damiano, NINDS). We presented a poster on long term monitoring of hearing and otoacoustic emissions in children receiving CNS radiation therapy at a professional meeting (Stakhovskaya et al, 2015).